gcr: Fix LICENSE

The contents of the COPYING file included in the current source code
package match those of LGPL-2.0 license, which seems to have been the
case since 2011 commit
https://gitlab.gnome.org/GNOME/gcr/-/commit/c6691faa0348ab087e99ab9bd9914e1d5e81fa14

(From OE-Core rev: f3ae58b741e4e6e3a5196ff75fcc4da6ee89d0b9)

(From OE-Core rev: 2db7a2538f7cbc54cbe6614a84ffc17bb422a4a8)

Signed-off-by: Niko Mauno <niko.mauno@vaisala.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>
Signed-off-by: Steve Sakoman <steve@sakoman.com>

meta/recipes-gnome/gcr/gcr_3.40.0.bb

@@ -5,7 +5,7 @@ GNOME desktop."
 HOMEPAGE = "https://gitlab.gnome.org/GNOME/gcr"
 BUGTRACKER = "https://gitlab.gnome.org/GNOME/gcr/issues"
 
-LICENSE = "GPL-2.0-only"
+LICENSE = "LGPL-2.0-only"
 LIC_FILES_CHKSUM = "file://COPYING;md5=55ca817ccb7d5b5b66355690e9abc605"
 
 DEPENDS = "p11-kit glib-2.0 libgcrypt gnupg-native \